I’m sorry if I posted in wrong section, couldn’t be more sure to categorize this question to a better section.
So, are there any group(s) of developers putting efforts through to generate a AI over Blockchain ? And if so, any Cryptos or ICOs? thanks. 
ICON have an AI on their blockchain. You might want to check them out.
ICON has a service called IISS, which stands for the ICON Incentives Scoring System.
This - according to them - is an AI based evaluation system; which is used to determine their C-reps in the system as well as the amount of ICX to be created / added / released at certain time intervals.
It explores the network and determines optimal incentive schemes to keep the network vitalised. It appears to carry a degree of machine learning in it as it needs to accumulate data in the initial stages of its life, and will likely continue doing so as the network grows.
So it is an AI that helps in determining which nodes will be accepted (for a time period) as representative nodes and how many new coins to issue on an approximate annual basis (which I imagine will be changed to deeper play against network needs through machine learning).
One area where I think AI could make a huge difference is in existing blockchain technologies that use PoW.
AI has already proven to very efficient in optimizing energy consumption, as an example, Deepmind AI is used by Google and has managed to reduce the cooling cost for Google’s data centres by up to 40%. If something to this extend can be built on to bitcoin’s blockchain and redistributes the hashpower that is going to waste in mining to fullfill other requirements (faster transactions, integration between networks, the lightning network for example, this could make a substantial difference in Bitcoins environmental footprint.
How you’d do this? I don’t have a clue 
Obviously, mining operations could also use Deepmind to cool their own facilities more efficiently, and as such reduce their own carbon footprint; which would be a good thing, but which would only partially help with reducing the massive energy waste that exist in PoW.
Just out of curiosity, what type of AI implementation(s) would you expect / are you looking for in regards to blockchain implementations?